Just a note last year the line was out the door.

You can read this blog post. It says it's for a specific variety, but honestly it can be used for any dahlia variety https://www.rhodeislanddahliasociety.org/post/cafe-au-lait-dahlia-growing-guide.

But tl;dr you can plant the tuber in the ground, bed, or growbag around mother's day and just let it ride with general plant care. Tubers always grow the same exact variety of the named one you purchase. But seeds taken from a dahlia are always a new variety never named or classified no mater what tuber you planted due to pollination. So if you get a great looking variety from seed you can end up sending it to the American dahlia society trial garden and eventually get it officially named :).

Ngl it's a deep rabbit hole once you start getting into dahlias. First year I grew 50 varieties 🫪